BR112021005391B1 - BIMODAL ETHYLENE-CO-1-HEXENE COPOLYMER COMPOSITION, METHOD FOR SYNTHESISTING THE BIMODAL ETHYLENE-CO-1-HEXENE COPOLYMER COMPOSITION, TUBE, METHOD FOR PRODUCING A TUBE AND MANUFACTURED ARTICLE - Google Patents

Abstract

BIMODAL COPOLYMER COMPOSITION, METHOD TO SYNTHESIS THE BIMODAL COPOLYMER COMPOSITION, TUBE, METHOD FOR PRODUCING A TUBE, AND, MANUFACTURED ARTICLE. It is a bimodal ethylene-co-1-hexene copolymer composition that essentially consists of a higher molecular weight component and a lower molecular weight component and, when in molten form at 190 degrees Celsius, is characterized by superior performance. fusion property performance defined by a combination of melt index (5 kg), melt strength and optionally shear thinning properties and, when in solid form, is characterized by a slow crack growth property performance defined by a combination of strain hardening modulus and accelerated full notch creep test performance. A blown film consisting essentially of a bimodal ethylene-co-1-hexene copolymer composition. A method for synthesizing ethylene-co-1-hexene bimodal copolymer composition. A method for producing blown film. A manufactured article comprising ethylene-co-1-hexene bimodal copolymer composition.

Description

Field

[0001] Polyethylene copolymer compositions, tubes and related methods.

Introduction

[0002] Patents and patent application publications within or about the field of invention to which the present invention relates include US documents No. 2016/0068623 A1; US 2016/0297907 A1; WO 2016/188703 A1; WO 2017/009058 A1; WO 2017/093008 A1; WO 2017/132092 A1; EP1985660B2’ EP2285896B1; US 5,332,706; US 5,882,750; US 6,989,344 B2; US 7,078,467 B1; US 7,090,927 B2; US 7,157,531 B2; US 7,223,825 B2; US 7,300,988 B2; US 8,227,552 B2; US 8,497,329 B2; and US 9,051,458 B2.

[0003] Document WO 2018/147968 refers generally to polyethylene resins and methods of their production.

[0004] WO2016/168700 provides the description of a polymerization catalyst system, a method of using the polymerization catalyst system and a polymer produced with the catalyst system. The polymerization catalyst system has a non-metallocene catalyst and a metallocene catalyst. The metallocene catalyst has the formula: wherein R1 and R2 are each independently phenyl, methyl, chlorine, fluorine or a hydrocarbyl group.

[0005] Document WO 2018/095772 describes a polymeric composition and a process for producing this composition comprising a base resin are disclosed herein. The base resin includes a very high molecular weight component, a low molecular weight component, and a high molecular weight component having a weight average molecular weight greater than the weight average molecular weight of the low molecular weight component, but less than the weight average molecular weight. ponderal. of the very high molecular weight component. An amount of the very high molecular weight component in the base resin is 0.5 to 8% by weight. The very high molecular weight component has a viscosity average molecular weight greater than 1100 kg/mol. The composition has an FRR21/5 equal to or greater than 38, a melt flow rate MFR21 equal to or greater than 6.5 g/10 min, and a viscosity at a shear stress of 747 Pa (eta747) of 450 to 3000 kPas.

summary

[0006] The present invention relates to a bimodal ethylene-co-1-hexene copolymer composition that consists essentially of a higher molecular weight component (HMw) and a lower molecular weight component (LMw) and, when in molten form at 190 degrees Celsius (°C), is characterized by a melt property performance defined by a combination of melt flow index (5 kg), melt strength and optionally shear thinning properties and when in solid form, it is characterized by a slow crack growth property performance defined by a combination of strain hardening modulus and full accelerated creep test (FNCT) performance ("the bimodal ethylene-co-copolymer composition" 1-hexene"). With “consists essentially of”, the ethylene-co-1-hexene bimodal copolymer composition is free of a third or more distinct components as determined by gel permeation chromatography (GPC) measured in accordance with the GPC Test Method For example, the composition of the bimodal ethylene-co-1-hexene copolymer is not trimodal or tetramodal.

[0007] A method for synthesizing the bimodal ethylene-co-1-hexene copolymer composition is also described, the method essentially consisting of polymerizing ethylene (monomer) and 1-hexene (comonomer) with a single catalyst system bimodal in a single fluidized bed, gas phase polymerization (FB-GPP) reactor under effective operating conditions, thereby producing the bimodal ethylene-co-1-hexene copolymer composition. With “essentially consists of”, the method is free of Ziegler-Natta catalysts and chromium catalysts (containing Cr, e.g. chromium oxide catalysts), and the polymerization is carried out in a single reactor (i.e. in the FB reactor - GPP), and the operating conditions are effective to make the ethylene-co-1-hexene bimodal copolymer composition with the combination of melt index (I5), melt strength and, optionally, shear thinning properties and the combination of strain hardening modulus and accelerated FNCT performance. Effective operating conditions include reactor bed temperature, hydrogen to ethylene molar ratio (H2/C2) and 1-hexene to ethylene molar ratio (C6/C2). Other than that, the method is not particularly limited.

[0008] In one embodiment the present invention describes a tube consisting essentially of the bimodal ethylene-co-1-hexene copolymer composition. The tube is characterized by enhanced (increased) inhibition of slow crack growth as measured by accelerated FNCT performance. With "consist essentially of", the film is free of other polyolefin polymers, but otherwise its constituents are not particularly limited.

[0009] Also described in the present application is a method of manufacturing a tube, the method comprising melting the ethylene-co-1-hexene bimodal copolymer composition to provide a melt thereof; extrude the melt into a starting tube; optionally resize the tube; and cool the initial or resized tube. The method can be conducted using a tube forming machine.

[0010] The present invention also provides the description of a manufactured article comprising the bimodal ethylene-co-1-hexene copolymer composition.

Detailed Description

[0011] Certain modalities described below are incorporated into this document by way of reference as numbered aspects to facilitate cross-referencing.

[0012] Aspect 1. An ethylene-co-1-hexene bimodal copolymer composition having a density of 0.945 to 0.960 grams per cubic centimeter (g/cm3), measured in accordance with ASTM D792-13, Method B; a molecular mass dispersion (Mw/Mn), θM, of 11.0 to 25.0, where Mw and Mn are measured according to the Gel Permeation Chromatography (GPC) Test Method; and consisting essentially of a higher molecular weight ethylene-co-1-hexene copolymer component (HMw component), with a molecular weight distribution (Mw/Mn) greater than 3.75 (> 3.75), alternatively of 3.76 to 10.0, alternatively from 3.80 to 9.40, and a lower molecular weight polyethylene homopolymer component or a lower molecular weight ethylene-co-1-hexene copolymer component (LMw component) , wherein the LMw component has a molecular weight distribution (Mw/Mn) of 2.75 to 3.35; and with a divided component fraction characterized by a weight fraction of the HMw component of 35.0 to 65.0% by weight, alternatively of 36.0 to 50.0% by weight and a weight fraction of the LMw component fraction from 65.0 to 35.0% by weight, alternatively from 64.0 to 50.0% by weight, respectively, of the combined weight of the HMw and LMw components, measured in accordance with the GPC test method; and wherein, when in melt form at 190°C, the ethylene-co-1-hexene bimodal copolymer composition is characterized by the properties (a), (b) and optionally (c): (a) a flow index melt strength (5 kg) (I5 or MFI5) of 0.15 to 0.30 grams for 10 minutes (g/10 min), (b) peak melt strength of 18 to 29 centiNewtons (cN) and, optionally, (c) shear thinning index, q0.01/q100, is 96 to 125; and, when in solid form, the bimodal ethylene-co-1-hexene copolymer composition is characterized by properties (d) and (e): (d) strain hardening modulus of 50 to 75 megapascals (MPa) and ( e) accelerated full notch creep test (FNCT) performance from 401 to 700.0 hours; wherein the melt flow index (5 kg) is measured in accordance with ASTM D1238-13 (190 °C, 5.0 kg), the shear thinning index is measured in accordance with Thinning Index Test Method shear strength(190°C), peak melt strength is measured at the highest peak on a graph of melt strength versus a speed range of 10 to 50 millimeters per second (mm/s), in accordance with Method of Melt Strength Test (described here, Gottfert Rheotens tester, 190 °C)., strain hardening modulus is measured in accordance with ISO 18488:2015, and accelerated FNCT performance is measured in accordance with ISO 16770 : 2004 at 90 °C and an actual stress of 5.0 MPa in 2 weight percent (wt%) lauramine oxide in water. The “/” means division. Properties (a) to (c) are collectively fusion properties. In some respects the composition is not, alternatively it is characterized by property (c). Properties (d) and (e) are properties of the resin. The bimodal ethylene-co-1-hexene copolymer composition may consist essentially of the higher molecular weight ethylene-co-1-hexene copolymer component and the lower molecular weight polyethylene homopolymer component. The bimodal ethylene-co-1-hexene copolymer composition may consist essentially of the higher molecular weight ethylene-co-1-hexene copolymer component and the lower molecular weight ethylene-co-1-hexene copolymer component.

[0013] Aspect 2. The ethylene-co-1-hexene bimodal copolymer composition of aspect 1 characterized by any of the property limitations (i) to (viii): (i) the density is 0.9450 to 0 .9590 g/cm3, alternatively 0.9480 to 0.9560 g/cm3, alternatively 0.9485 to 0.9585 g/cm3, measured in accordance with ASTM D792-13, Method B; (ii) the division of the component fraction is characterized by a weight fraction of the HMw component of 44.0 to 52.0% by weight, alternatively from 48 to 56.0% by weight; and a weight fraction of the LMw component fraction of 56.0 to 48.0% by weight, alternatively from 52.0 to 44.0% by weight, respectively, of the combined weight of the HMw and LMw components, measured in accordance with the GPC test method; (iii) the molecular mass dispersion (Mw/Mn), DM, is 11.0 to 23.0, alternatively 15.0 to 25, alternatively 15.0 to 22.5, where Mw and Mn are measured in accordance with the GPC Test Method; (iv) the (a) MFI5 is 0.15 to 0.24 g/10 min, alternatively 0.180 to 0.30 g/10 min, alternatively 0.181 to 0.214 g/10 min, alternatively 0.181 to 0.185 g /10 min, alternatively from 0.205 to 0.214 g/10 min; (v) the (c) shear thinning index, r|0.01/r|100, is 99 to 115, alternatively 100.0 to 110.0; (vi) the (b) peak melt strength is 20.0 to 28 cN, alternatively 21 to 29 cN, alternatively 22 to 28 cN, alternatively 23 to 27 cN, alternatively 24 to 26 cN; (vii) the (d) strain hardening modulus is 55 to 70.0 MPa; (viii) (e) Accelerated FNCT performance is 401 to 600.0 hours, alternatively 401 to 540 hours, alternatively 460 to 600 hours, alternatively 465 to 535 hours. Alternatively, the ethylene-co-1-hexene bimodal copolymer composition is characterized by a combination of two or more limitations according to any one of limitations (ix) to (xxxviii): (ix) both (i) and (ii ); (x) both (i) and (iii); (xi) both (i) and (iv); (xii) both (i) and (v); (xiii) (i) and (vi); (xiv) both (i) and (vii); (xv) both (i) and (viii); (xvi) both (ii) and (iii); (xvii) both (ii) and (iv); (xviii) both (ii) and (v); (xix) both (ii) and (vi); (xx) both (ii) and (vii); (xxi) both (ii) and (viii); (xxii) both (iii) and (iv); (xxiii) both (iii) and (v); (xxiv) both (iii) and (vi); (xxv) both (iii) and (vii); (xxvi) both (iii) and (viii); (xxvii) both (iv) and (v); (xxviii) both (iv) and (vi); (xxix) both (iv) and (vii); (xxx) both (iv) and (viii); (xxxi) both (v) and (vi); (xxxii) both (v) and (vii); (xxxiii) both (v) and (viii); (xxxiv) both (vi) and (vii); (xxxv) both (vi) and (viii); (xxxvi) both (vii) and (viii); (xxxvii) any seven of (i) to (viii); and (xxxviii) each of (i) to (viii).

[0014] Aspect 3. The bimodal ethylene-co-1-hexene copolymer composition of aspect 1 or 2 further characterized by any of the melt property limitations (i) to (iii): (i) a high melt index charge melting from 1 to 10 g/10 min, alternatively from 4 to 10 g/10 min, alternatively from 1 to 7 g/10 min, alternatively from 5.0 to 6.0 g/10 min, measured in accordance with to ASTM D1238-13 (190 °C, 21.6 kg, HLMI or I21); (ii) a melt flow ratio I21/I5 ("MFR5") of 20 to 40, alternatively of 26 to 40, alternatively of 20 to 33, alternatively of 26 to 33, wherein the I21 and I5 values used to calculate o MFR5 are each in g/10 min and are measured in accordance with ASTM D123813 (190 °C, 21.6 kg, "I21"; and 190 °C, 5.0 kg, "I5", respectively ); (iii) both (i) and (ii).

[0015] Aspect 4. The bimodal ethylene-co-1-hexene copolymer composition of any one of aspects 1 to 3 further characterized by any of the resin property limitations (i) to (iv): (i) a weight average molecular weight (Mw) of 300,000 to 400,000 grams per mole (g/mol), alternatively of 300,000 to 360,000 g/mol, alternatively of 330,000 to 400,000 g/mol, alternatively of 330,000.0 to 356,000 g/mol; (ii) a number average molecular weight (Mn) of 10,000 to 30,000 grams g/mol, alternatively of 10,000 to 24,000 g/mol, alternatively of 14,000 to 30,000 g/mol, alternatively of 14,000.0 to 24,000 g/mol; (iii) a z-average molecular weight (Mz) of 2,000,000 to 3,400,000 g/mol, alternatively of 2,000,000 to 3,100,000 g/mol, alternatively of 2,400,000 to 3,400,000 g/mol, alternatively from 2,400,000 to 3,100,000 g/mol; (iv) a butyl branching frequency per 1,000 carbon atoms (bbf/1,000C) of 1.2 to 1.5, alternatively of 1.25 to 1.50, alternatively of 1.2 to 1.44, alternatively from 1.27 to 1.44, as measured according to the Butyl Branch Frequency Test Method; where Mw, Mn and Mz are measured according to the GPC test method. Alternatively, by any of limitations (v) to (xii): (v) both (i) and (ii); (vi) both (i) and (iii); (vii) both (i) and (iv); (viii) both (ii) and (iii); (ix) both (ii) and (iv); (x) both (iii) and (iv); (xi) any three of (i) and (iv); and (xii) each of (i) to (iv).

[0016] Aspect 5. A method for synthesizing the bimodal ethylene-co-1-hexene copolymer composition, according to any one of aspects 1 to 4, the method essentially consisting of copolymerizing ethylene (monomer) and 1-hexene (comonomer) and copolymerize fresh ethylene and, optionally, fresh 1-hexene, with a combination of a bimodal catalyst system and an equilibrium catalyst in the presence of molecular hydrogen gas (H2) and, optionally, a condensing agent induced (ICA) in a polymerization reactor (e.g., a fluidized bed, gas phase polymerization reactor (FB-GPP reactor)) under effective polymerization conditions to provide an initial ethylene-co-1-hexene bimodal copolymer; in which the bimodal catalyst system is produced by contacting a first activator with bis(2-(pentamethylphenylamido)ethyl)-amine zirconium dibenzyl and a dimethyl (methylcyclopentadienyl)(1,3-dimethyl-4,5,6,7 -tetrahydroindenyl)zirconium; wherein the equilibrium catalyst is produced by contacting a second activator with (methylcyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl) zirconium dimethyl; wherein the first and second activators are the same or different; and wherein effective polymerization conditions comprise a reaction temperature of 90°C (°C) to 110° Celsius (C), alternatively 98°C to 107°C, alternatively 99° to 106°C in a polymerization reactor , fluidized bed, gas phase polymerization (FB-GPP); a molar ratio of molecular hydrogen gas to ethylene (H2/C2 molar ratio) of 0.001 to 0.0050, alternatively 0.0020 to 0.0030, alternatively 0.00220 to 0.00290; and a molar ratio of 1-hexene ("C6") to ethylene (C6/C2 molar ratio) of 0.00450 to 0.01000, alternatively of 0.0050 to 0.0080, alternatively of 0.0055 to 0, 0075. The first activator may be an alkylaluminoxane (alkylalumoxane) and the second activator, independently, may be an alkylaluminoxane or an alkylaluminoxane compound.

[0017] Aspect 6. The method, according to aspect 5, which further essentially consists of removing the ethylene-co-1-hexene bimodal copolymer composition from the reactor (for example, the FB-GPP reactor) to provide a removed ethylene-co-1-hexene bimodal copolymer composition. In some aspects, the removed ethylene-co-1-hexene bimodal copolymer composition may be purged with an inert gas (e.g., N2) to remove scaled hydrocarbons therefrom and/or treated with a stream of humidified nitrogen (N2 ) to deactivate, in situ, any residual amount of the bimodal catalyst system contained therein to provide a purged bimodal ethylene-co-1-hexene copolymer composition. In some aspects, the removed or purged bimodal ethylene-co-1-hexene copolymer composition is degassed to remove volatile organic compounds therefrom to provide a degassed bimodal ethylene-co-1-hexene copolymer composition. In some aspects, a melt of the removed, purged or degassed bimodal ethylene-co-1-hexene copolymer composition may be oxygen adapted in an extruder to result in an oxygen adapted bimodal ethylene-co-1-hexene copolymer composition. . In some aspects, the removed, purged, degassed or oxygen-adapted bimodal ethylene-co-1-hexene copolymer composition is independently pelletized to give pellets thereof (pelletized bimodal ethylene-co-1-hexene copolymer composition). The initial, removed, purged, degassed, oxygen adapted and pelletized embodiments of the bimodal ethylene-co-1-hexene copolymer composition are collectively referred to as “the bimodal ethylene-co-1-hexene copolymer composition”, which may be that according to any one of aspects 1 to 4. The ethylene-co-1-hexene bimodal copolymer composition may be its initial, removed, purged, degassed or pelletized embodiment. The method may further comprise a step. of combining the bimodal ethylene-co-1-hexene copolymer composition with one or more pipe additives useful in polyethylene pipes. The combination may comprise melt mixing one or more pipe additives into a melt of the copolymer composition. bimodal ethylene-co-1-hexene to provide a bimodal ethylene-co-1-hexene/additive copolymer formulation. Alternatively, the combination may comprise soaking or injecting the one or more tube additives into the pellets of the bimodal copolymer composition. of pelletized ethylene-co-1-hexene to provide the bimodal ethylene-co-1-hexene/additive copolymer formulation.

[0018] Aspect 7. A tube consisting essentially of the bimodal ethylene-co-1-hexene copolymer composition of any one of aspects 1 to 4 ("the tube"), alternatively, the bimodal ethylene-co-1-hexene copolymer formulation. -1- hexene/additive. The transitional phrase “consists essentially of” means that the tube is free from other polyolefin polymers, but otherwise its constituents are not particularly limited. The tube can be used in fluid (gas and/or liquid). In some aspects, the ethylene-co-1-hexene bimodal copolymer composition of the tube is not the oxygen-adapted ethylene-co-1-hexene bimodal copolymer composition.

[0019] Aspect 8. A method for producing a tube, wherein the method comprises the method of producing a tube, wherein the method comprises the steps of: (A), (B1) or (B2), optionally ( C) and (D): (1) melting the ethylene-co-1-hexene bimodal copolymer composition, as defined in any one of aspects 1 to 4, to provide a melt thereof; (B1) extruding the melt through an annular die configured to form a cylinder, so as to produce an initial solid-wall cylinder from the bimodal ethylene-co-1-hexene copolymer composition; or (B2) extruding and spirally winding the melt around a mandrel configured to form an unsealed seam profile wall so as to produce an unsealed seam profile wall and heat fusing the unsealed seam profile wall unsealed seam profile wall to produce an initial sealed seam wall cylinder; (C) optionally resizing the initial solid wall cylinder or the initial sealed seam wall cylinder to produce a resized wall cylinder with a different diameter; and (D) cooling the initial solid wall cylinder, the initial seam wall cylinder, or the resized wall cylinder, thereby forming a solid wall tube or a solid wall tube or a sealed seam wall tube, respectively.

[0020] Step (B1), related to aspect 8, can be carried out using a solid wall tube forming machine, and step (B2), using a mandrel and a solid wall tube forming and sealing machine. spiral profile wall. A tube consists essentially of the bimodal ethylene-co-1-hexene copolymer according to any one of aspects 1 to 4 ("the tube"). The transitional phrase “consists essentially of” means that the tube is free from other polyolefin polymers, but otherwise its constituents are not particularly limited.

[0021] Aspect 9. A tube produced by the method according to aspect 8 and consisting essentially of the bimodal ethylene-co-1-hexene copolymer composition according to any one of aspects 1 to 4 ("the tube "). With "consists essentially of", the tube is free of other polyolefin polymers, but otherwise its constituents are not particularly limited. The tube may be characterized by enhanced (increased) slow crack growth. The tube may be used in fluid transport applications. The pipe can be characterized by meeting the pipe industry specifications for a PE100 or PE100 RC pipe.

[0022] Aspect 10. Manufactured article comprising the bimodal ethylene-co-1-hexene copolymer composition, as defined in any of aspects 1 to 4, wherein the manufactured article is not a tube.

[0023] The ethylene-co-1-hexene bimodal copolymer composition is not a physical mixture or a molten mixture of two different copolymers, made separately or of a separately made copolymer and a separately made homopolymer. The ethylene-co-1-hexene bimodal copolymer composition is made by a method using a bimodal catalyst system in a single reactor, which method beneficially allows the Mw/Mn of the HMw component to be greater than the Mw/Mn of a comparative HMw component made in the staged reactor, where the staged reactor uses the same catalyst to make the HMw and LMw components

[0024] In some aspects, the ethylene-co-1-hexene bimodal copolymer composition may have a transition metal content, alternatively a Zr content, of less than 10 parts by weight per million (ppm), measured from according to inductively coupled plasma mass spectrometry (ICP-MS).

Definitions

[0025] Activator. A substance, other than the catalyst or one of the substrates, that increases the rate of a catalyzed reaction without being consumed. Typically, the activator contains aluminum and/or boron.

[0026] Bimodal. Two, and only two, modalities or modes.

[0027] Bimodal, in reference to a copolymer composition (for example, the ethylene-co-1-hexene copolymer composition), means a composition that consists essentially of a component of higher molecular weight and a component of lower molecular weight. molecular weight, wherein the higher molecular weight component consists of a first group of polymer macromolecules produced by a first catalyst in a first reactor under a first set of molecular weight effective polymerization process conditions (e.g., bed temperature of the first reactor, molar ratio of the first gas H2/C2 and/or molar ratio of the first comonomer/monomer) and the lower molecular weight component consists of a second group of polymer macromolecules produced by a second catalyst in a second reactor under a second set of molecular weight effective polymerization process conditions (e.g., second reactor bed temperature, second gas H2/C2 molar ratio, and/or second comonomer/monomer molar ratio), wherein at least one of the following differences are present: (a) the first catalyst is different in ligand and/or catalytic metal composition than that/those of the second catalyst; (b) the first reactor is different from the second reactor or the first and second reactors are the same reactor, but the polymerization reaction that produces the higher molecular weight component is produced in a different time than the polymerization reaction that produces the lowest molecular weight component; (c) at least one of the first set of molecular weight effective polymerization process conditions is different from that of the second set of molecular weight effective polymerization process conditions. Bimodal polymer compositions include post-reactor blends and reactor blends (in which the lower and higher molecular weight components are synthesized in the same reactor). The bimodal copolymer composition can be characterized by two peaks separated by a minimum distinguishable location between them on a plot of dW/dLog(Mw) on the y-axis versus Log(Mw) on the x-axis to provide a Permeation Chromatography chromatogram in Gel (GPC), where Log(Mw) and dW/dLog(Mw) are as defined herein and are measured by the Gel Permeation Chromatography (GPC) Test Method described herein.

[0028] Bimodal, when referring to a catalyst system, means a catalyst system that contains two different catalysts to catalyze the same polymerization process (for example, olefin polymerization) and produce a bimodal polymer composition. Two catalysts are different if they differ from each other in at least one of the following characteristics: (a) their catalytic metals are different (Ti versus Zr, Zr versus Hf, Ti versus Hf; non-activating metals such as Al); (b) one catalyst has a functional ligand covalently bound to its catalytic metal and the other catalyst is free of functional ligands bound to its catalytic metal; (c) both catalysts have functional ligands covalently bonded to their catalytic metal and the structure of at least one of the functional ligands of one of the catalysts is different from the structure of each of the functional ligands of the other catalyst (e.g., cyclopentadienyl versus propylcyclopentadienyl or butylcyclopentadienyl versus (pentamethylphenylamido)ethyl)-amine); and (d) for catalysts disposed on a support material, the compositions of the support materials are different. Functional ligands do not include leaving groups X, as defined later. Two catalysts of a bimodal catalyst system can be disposed on the same support material, on the same particles of the same support material, or each on different particles of the same support material. The same catalyst, in terms of catalytic metal and ligands, in which a portion thereof is disposed on a support material and a different portion thereof is dissolved in an inert solvent, the different portions do not in themselves constitute a system bimodal catalyst.

[0029] Catalyst. A material that enhances the rate of a reaction (for example, the polymerization of ethylene and 1-hexene) and is not completely consumed by it.

[0030] Catalytic system. A combination of a catalyst, per se, and a complementary material, such as a modifying compound to attenuate the reactivity of the catalyst, a support material on which the catalyst is disposed, a carrier material on which the catalyst is disposed, or a combination of two or more of the same, or a reaction product of a reaction of the same.

[0031] Consist essentially of, consists (or consist) essentially of, and so on. Partially closed expressions that exclude anything that would affect the basic, novel features they describe, but otherwise allow anything else. In some aspects, either, alternatively, each “comprising” or “comprising” may be replaced by “consisting essentially of” or “consisting essentially of”, respectively; alternatively by “which consists of” or “consists of”, respectively.

[0032] Consist of and consists of. Closed expressions that exclude anything not specifically described by the limitation they modify. In some aspects, either, alternatively, each expression “consisting essentially of” or “consisting essentially of” may be replaced by the expression “consisting of” or “consists of”, respectively.

[0033] Dry. Generally, a moisture content of 0 to less than 5 parts per million based on total parts by weight. Materials that feed the reactor (or reactors) during a polymerization reaction are dried.

[0034] Food. Amount of reactant or reactant that is added or “used to feed” a reactor. In continuous polymerization operation, each feed, independently, can be continuous or intermittent. Quantities or “feeds” can be measured, for example, by dosing, to control quantities and relative amounts of the various reactants and reagents in the reactor at any given time.

[0035] Power line. A tube or conduit structure for transporting a feed.

[0036] Inert. Generally, it does not (noticeably) reactive or does not (noticeably) interfere with the polymerization reaction of the invention. The term “inert” as applied to purge gas or ethylene feed means a molecular oxygen (O2) content of 0 to less than 5 parts per million based on the total parts by weight of the purge gas or ethylene feed. .

[0037] Metallocene catalyst. Homogeneous or heterogeneous material that contains a cyclopentadienyl metal-ligand complex and that enhances olefin polymerization reaction rates. Substantially single location or dual location. Each metal is a Ti, Zr, or Hf transition metal. Each cyclopentadienyl ligand, independently, is an unsubstituted cyclopentadienyl group or a hydrocarbyl-substituted cyclopentadienyl group. In some aspects, the metallocene catalyst has two cyclopentadienyl ligands, and at least one, alternatively both cyclopentenyl ligands are independently a hydrocarbyl-substituted cyclopentadienyl group. Each hydrocarbyl-substituted cyclopentadienyl group can independently have 1, 2, 3, 4 or 5 hydrocarbyl substituents. Each hydrocarbyl substituent may independently be a (C1-C4)alkyl. Two or more substituents can be linked together to form a divalent substituent which, with carbon atoms of the cyclopentadienyl group, can form a ring.

[0038] Balance catalyst. An amount of a metallocene catalyst that is identical, except for an optional difference in group X, described later, to the metallocene catalyst of the bimodal catalyst system. The equilibrium catalyst is normally fed (e.g. to the FB-GPP reactor) as a solution of the catalyst dissolved in an inert liquid (non-polar, aprotic, e.g. hydrocarbon solvent). The equilibrium catalyst is used with the bimodal catalyst system to modify at least one property of the copolymer composition thus produced. Examples of this at least one property are: density, melt index I2, flow index I21, melt flow ratio (I21/I2) and molecular mass dispersion (Mw/Mn), θiM.

[0039] Ziegler-Natta catalysts. Heterogeneous materials that enhance olefin polymerization reaction rates by contacting inorganic titanium compounds, such as titanium halides supported on a magnesium chloride support, with an activator.

Reactor and polymerization method

[0040] In an illustrative pilot installation process to produce the bimodal ethylene-co-1-hexene copolymer, a fluidized bed gas phase polymerization reactor ("FB-GPP reactor") with a reaction zone sized at 304 .8 mm (twelve inches) in internal diameter and 2.4384 meters (8 feet) in straight side height and containing a fluidized bed of granules of bimodal ethylene-co-1-hexene copolymer composition. Configure the FB-GPP reactor with a recycle gas line to produce a recycle gas stream. Set up FB-GPP reactor with gas feed inlets and polymer product outlet. Introduce gaseous feed streams of ethylene and hydrogen together with comonomer (e.g. 1-hexene) from the FB-GPP reactor bed into the recycle gas line.

[0041] Polymerization operating conditions are any variable or combination of variables that can affect a polymerization reaction in the GPP reactor or a composition or property of a product of the ethylene-co-1-hexene copolymer composition produced in this way. Variables may include reactor design and size, catalyst composition and quantity; composition and amount of reagent; molar ratio of two different reagents; presence or absence of feed gases such as H2 and/or O2, molar ratio of feed versus reactive gases, absence or concentration of interfering materials (e.g. H2O), absence or presence of an induced condensing agent (ICA) , average polymer residence time in the reactor, partial pressures of constituents, monomer feed rates, reactor bed temperature (e.g., fluidized bed temperature), nature or sequence of process steps, time periods for transition between the steps. Variables other than those described or changed by the method or use may be kept constant.

[0042] When operating the polymerization method, control the individual flow rates of ethylene ("C2"), hydrogen ("H2") and 1-hexene ("C6" or "Cx" where x is 6) to ensure maintain a fixed comonomer to ethylene monomer gas molar ratio (Cx/C2, e.g., C6/C2) equal to a described value (e.g., 0.00560 or 0.00703), a constant hydrogen to gas molar ratio ethylene ("H2/C2") equal to a described value (e.g., 0.00229 or 0.00280), and a constant ethylene partial pressure ("C2") equal to a described value (e.g., 1,000 kPa) . Measure concentrations of all gases via the in-line gas chromatograph to understand and maintain the composition in the recycle gas stream. Maintain a reaction bed of growing polymer particles in a fluidized state by continuously flowing a makeup feed and recycling gas through the reaction zone. Use a superficial gas velocity of 0.49 to 0.67 meters per second (m/s) (1.6 to 2.2 feet per second (ft/s)). Operate the FB-GPP reactor at a total pressure of about 2,344 to about 2,413 kilopascals (kPa) (about 340 to about 350 pounds per square inch-gauge (psig)) and at an RBT of the first bed temperature. reactor described. Maintain the fluidized bed at a constant height by withdrawing a portion of the bed at a rate equal to the production rate of the particulate form of the ethylene-co-1-hexene bimodal copolymer composition, which production rate may be 10 to 20 kilograms per hour (kg/h), alternatively 13 to 18 kg/h. Removing the bimodal ethylene-co-1-hexene copolymer composition semicontinuously through a series of valves in a fixed volume chamber, wherein this removed bimodal ethylene-co-1-hexene copolymer composition is purged to remove encrusted hydrocarbons and treated with a stream of humidified nitrogen gas (N2) to deactivate any traces of residual catalyst. See the polymerization method described in this document.

[0043] The bimodal catalyst system can feed the polymerization reactor (or polymerization reactors) in "dry mode" or "wet mode", alternatively in dry mode, alternatively in wet mode. Dry mode is dry powder or granules. Wet mode is a suspension in an inert liquid such as mineral oil.

[0044] Induced condensation agent (ICA). An inert liquid useful for cooling materials in the polymerization reactor (or polymerization reactors) (e.g., a fluidized bed reactor); its use is optional. The ICA may be a (C5-C20)alkane, alternatively a (C11-C20)alkane, alternatively a (C5-C10)alkane, alternatively a (C5)alkane, for example pentane or 2-methylbutane; one hexane; a heptane; one octane; a nonane; a dean; or a combination of any two or more of them. The ICA may be 2-methylbutane (i.e., isopentane). Aspects of the polymerization method that use ICA can be referred to as induced condensation mode operation (ICMO). ICMO is described in documents No. US 4,453,399; US 4,588,790; US 4,994,534; US 5,352,749; US 5,462,999 and US 6,489,408. The concentration of ICA in the gas phase is measured using gas chromatography by calibrating the percentage peak area in mole percent (mol%) with a gas mixture standard of known concentrations of ad rem gas phase components. . The concentration of ICA can be 1 to 10 mol%, alternatively 3 to 8 mol%.

[0045] The polymerization method uses a gas phase polymerization (GPP) reactor, such as a stirred bed gas phase polymerization reactor (SB-GPP reactor) or a fluidized bed gas phase polymerization reactor (FB reactor -GPP), to produce the bimodal ethylene-co-1-hexene copolymer composition. Such reactors and methods are generally well known in the art. For example, the FB-GPP reactor/method may be described in US 3,709,853; US 4,003,712; US 4,011,382; USA 4,302,566; USA 4,543,399; US 4,882,400; US 5,352,749; US 5,541,270; EP-A-0 802 202; and Patent No. BE 839,380. These SB-GPP and FB-GPP polymerization processes and reactors mechanically agitate or fluidize by continuous flow of gaseous monomer and polymerization medium diluent within the reactor, respectively. Other useful reactors/processes contemplated include serial or multi-stage polymerization processes, as described in US 5,627,242; US 5,665,818; US 5,677,375; EP-A-0 794 200; EP-B1-0 649 992; EP-A-0 802 202 and EP-B-634421.

[0046] The polymerization conditions may also include one or more additives, such as a chain transfer agent or a promoter. Chain transfer agents are well known and may be alkyl metal, such as diethyl zinc. Promoters are known, as in US 4,988,783, and may include chloroform, CFCl3, trichloroethane and difluorotetrachloroethane. Prior to reactor startup, a sequestering agent can be used to react with moisture, and during reactor transitions, a sequestering agent can be used to react with excess activator. The sequestering agents may be trialkylaluminum. Gas phase polymerizations can be operated free of sequestering agents (not deliberately added). The polymerization conditions for the gas phase polymerization reactor/method may additionally include an amount (e.g., 0.5 to 200 ppm based on all feeds into the reactor) of static control agent and/or continuity additive, such as aluminum stearate or polyethyleneimine. The static control agent can be added to the FB-GPP reactor to inhibit the formation or accumulation of static charge therein.

[0047] Startup or restart of the GPP reactor can be illustrated with a fluidized bed, GPP reactor. Start-up of a recommissioned FB-GPP reactor (cold start) or restart of a transitioning FB-GPP reactor (hot start) includes a period of time that is prior to reaching the steady-state polymerization conditions of the step ( The). Start-up or restart may include the use of a pre-charged or loaded polymer seed, respectively, in the fluidized bed reactor. The polymer seed may be composed of a polyethylene powder, such as a polyethylene homopolymer or previously produced batch of ethylene-co-1-hexene bimodal copolymer composition.

[0048] Startup or restart of the FB-GPP reactor may also include gas atmosphere transitions that comprise purging air or other unwanted gas (or gases) from the reactor with a dry (anhydrous) inert purge gas, followed by purging of dry inert purge gas from the FB-GPP reactor with dry ethylene gas. The dry inert purge gas may consist essentially of molecular nitrogen (N2), argon, helium or a mixture of two or more thereof. When not in operation, before initialization (cold start), the FB-GPP reactor contains an air atmosphere. The dry inert purge gas can be used to sweep air from a recommissioned FB-GPP reactor during the early stages of startup to provide an FB-GPP reactor that has an atmosphere consisting of the dry inert purge gas. Prior to restart (e.g., after a change in seedings) a transitioning FB-GPP reactor may contain an unwanted ICA atmosphere or other unwanted gas or vapor. The dry inert purge gas may be used to sweep vapor or unwanted gas from the transitioning FB-GPP reactor during the initial stages of restart to provide an atmosphere consisting of the dry inert purge gas to the FB-GPP reactor. Any dry inert purge gas can itself be swept from the FB-GPP reactor with the dry ethylene gas. The dry ethylene gas may additionally contain molecular hydrogen gas such that the dry ethylene gas is used to feed the fluidized bed reactor as a mixture thereof. Alternatively, dry molecular hydrogen gas can be introduced separately and after the fluidized bed reactor atmosphere has been transferred to ethylene. Gas atmosphere transitions can be produced before, during, or after heating the FB-GPP reactor to the reaction temperature of the polymerization conditions.

[0049] Initialization or restart of the FB-GPP reactor also includes introducing feeds of reagents and reagents into it. Reactives include ethylene and alpha-olefin (e.g., 1-hexene). The reactants used to power the fluidized bed reactor include molecular hydrogen gas and induced condensation agent (ICA) and the bimodal catalyst system and equilibrium catalyst.

[0050] In one embodiment, the method uses a pilot-scale fluidized bed gas-phase polymerization reactor (pilot reactor) comprising a reactor vessel containing a fluidized bed of a powder of the bimodal ethylene-ethylene copolymer composition. co-1-hexene and a distributor plate, disposed above a lower head, and which defines a bottom gas inlet and which has an expanded section, or cyclone system, at the top of the reactor vessel to decrease the amount of particles fine resin that may escape from the fluidized bed. The expanded section defines a gas outlet. The pilot reactor further comprises a compressor blower with sufficient power to circulate, in a closed loop or continuous cycle, gas around the gas outlet in the expanded section at the top of the reactor vessel to the lower gas inlet. from the pilot reactor and through the distribution board and fluidized bed. The pilot reactor additionally comprises a cooling system to remove polymerization heat and maintain the fluidized bed at a target temperature. Gas compositions, such as ethylene, alpha-olefin (e.g., 1-hexene), and hydrogen, which are used to power the pilot reactor, are monitored by an in-line gas chromatograph in the closed loop loop in order to maintain concentrations specifications that define and allow the control of polymer properties. The bimodal catalyst system can be fed as a slurry or dry powder into the Pilot Reactor from high-pressure devices, whereby the slurry is fed through a syringe pump and the dry powder is fed through a metered disk. . The bimodal catalyst system typically enters the fluidized bed at the bottom 1/3 of its bed height. The pilot reactor further comprises a means of weighing the fluidized bed and isolation ports (Product Discharge System) for discharging the powder of the ethylene-co-1-hexene bimodal copolymer composition from the reactor vessel. in response to an increase in fluidized bed weight as the polymerization reaction proceeds.

[0051] In some embodiments, the FB-GPP reactor is a commercial scale reactor, such as a UNIPOL™ or UNIPOL™ II reactor, which are available from Univation Technologies, LLC, a subsidiary of The Dow Chemical Company, Midland, Michigan, USA.

Catalysts, support materials, activators

[0052] The bimodal catalyst system used in the method to synthesize can essentially consist of a metallocene catalyst and a non-metallocene molecular catalyst, which are different in functional ligand and/or catalytic metal M. The bimodal catalyst system can also consist, essentially, on a solid support material and/or on at least one activator and/or on at least one kind of activator, which is a by-product of the reaction of the metallocene catalyst or the non-metallocene molecular catalyst with the first activator . The metallocene catalyst of the bimodal catalyst system may be (methylcyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl)zirconium dimethyl and the non-metallocene molecular catalyst of the bimodal catalyst system may be bis(2- (pentamethylphenylamido)ethyl)-zirconium amine.

[0053] Without limitation by theory, it is believed that zirconium bis(2-(pentamethylphenylamido)ethyl)-amine dibenzyl is effective for producing the HMw component of the ethylene-co-1-hexene bimodal copolymer composition and the (methylcyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl)zirconium dimethyl is independently effective for producing the LMw component of the ethylene-co-1-hexene bimodal copolymer composition. The molar ratio of the two catalysts of the bimodal catalyst system can be based on the molar ratio of their respective catalytic metal atom contents (M, e.g. Zr), which can be calculated from the weights of the ingredients thereof or can be measured analytically.

[0054] The catalysts of the bimodal catalyst system can be disposed by spray drying on a solid support material before coming into contact with an activator. The solid support material may be uncalcined or calcined before coming into contact with the catalysts. The solid support material may be a hydrophobic fumed silica (e.g., a fumed silica treated with dimethyldichlorosilane). The bimodal catalyst system (unsupported or supported) may be in the form of a free-flowing, powdered, particulate solid.

[0055] Support material. The support material may be an inorganic oxide material. The terms "support" and "support material" are the same as those used herein and refer to a porous inorganic substance or organic substance. In some embodiments, desirable support materials may be inorganic oxides that include oxides of Group 2, 3, 4, 5, 13 or 14, alternatively Group 13 or 14 of atoms. Examples of inorganic oxide-type support materials are silica, alumina, titania, zirconia, thoria and mixtures of any two or more of these inorganic oxides. Examples of such mixtures are silica-chromium, silica-alumina and silica-titania.

[0056] The inorganic oxide support material is porous and has variable surface area, pore volume and average particle size. In some embodiments, the surface area is 50 to 1,000 square meters per gram (m2/g) and the average particle size is 20 to 300 micrometers (μm). Alternatively, the pore volume is 0.5 to 6.0 cubic centimeters per gram (cm3/g) and the surface area is 200 to 600 m2/g. Alternatively, the pore volume is 1.1 to 1.8 cm3/g and the surface area is 245 to 375 m2/g. Alternatively, the pore volume is 2.4 to 3.7 cm3/g and the surface area is 410 to 620 m2/g. Alternatively, the pore volume is 0.9 to 1.4 cm3/g and the surface area is 390 to 590 m2/g. Each of the above properties is measured using conventional techniques known in the art.

[0057] The support material may comprise silica, alternatively amorphous silica (not quartz), alternatively an amorphous silica with a large surface area (for example, from 500 to 1,000 m2/g). These silicas are commercially available from several sources, including Davison Chemical Division of WR Grace and Company (e.g., Davison 952 and Davison 955 products) and PQ Corporation (e.g., product ES70). Silica can be in the form of spherical particles, which are obtained by a spray drying process. Alternatively, product MS3050 is a silica from PQ Corporation that is not spray dried. As purchased, all of these silicas are not calcined (i.e., not dehydrated). Silica that is calcined before purchase can also be used as a support material.

[0058] Before contacting a catalyst, the support material can be pretreated by heating the support material in air to provide a calcined support material. Pretreatment comprises heating the support material to a peak temperature of 350° to 850°C, alternatively 400° to 800°C, alternatively 400° to 700°C, alternatively 500° to 650°C , and for a period of time from 2 to 24 hours, alternatively from 4 to 16 hours, alternatively from 8 to 12 hours, alternatively from 1 to 4 hours, thus producing a calcined support material. In some aspects, the support material is a calcined support material.

[0059] The equilibrium catalyst can be any one of the metallocene catalysts mentioned above. For convenience, the equilibrium catalyst is fed into solution in a hydrocarbon solvent (e.g., mineral oil or heptane). The hydrocarbon solvent may be an alkane or a mixture of alkanes, wherein each alkane independently has from 5 to 20 carbon atoms, alternatively from 5 to 12 carbon atoms, alternatively from 5 to 10 carbon atoms. Each alkane, independently, can be acyclic or cyclic. Each acyclic alkane, independently, can be straight-chain or branched-chain. The acyclic alkane can be pentane, 1-methylbutane (isopentane), hexane, 1-methylpentane (isohexane), heptane, 1-methylhexane (isoheptane), octane, nonane, decane or a mixture of two or more of the same. The cyclic alkane can be cyclopentane, cyclicohexane, cyclicheptane, cyclooctane, cyclononane, cyclodecane, methylcyclopentane, methylcyclohexane, dimethylcyclopentane or a mixture of two or more thereof.

[0060] For solubility in the hydrocarbon solvent, typically, each of the X group of the equilibrium catalyst is, independently, hydrocarbyl (e.g., benzyl, a (C1-C5)alkyl or a (C2-C5)alkenyl; e.g. example, methyl or ethyl) or - CH2Si(CH3)3. The X groups of the equilibrium catalyst may be different from the X groups of the metallocene catalyst of the bimodal catalyst system. However, upon activation by contact thereof with an activator, the species of active catalyst resulting from the activation of the equilibrium catalyst is essentially the same as the species of active catalyst resulting from the activation of the metallocene catalyst of the bimodal catalyst system. For example, the metallocene catalyst of the bimodal catalyst system may be (methylcyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl) zirconium dichloride (each X is Cl), and the equilibrium catalyst may be dialkyl of (methylcyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl) zirconium (e.g. dimethyl, where X is CH3). After activation by treating it with a suitable activator or cocatalyst, either (methylcyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl) zirconium dichloride or (methylcyclopentadienyl)(1,3 -dimethyl-4,5,6,7-tetrahydroindenyl) zirconium effectively produce the same species of activated catalyst.

[0061] Activator. Each catalyst in the bimodal catalyst system is activated by contact with the first activator. The balancing catalyst is activated upon contact with the second activator. Additional activators can be used. The activator can be the same or different from each other and, independently, can be a Lewis acid, a non-coordinating ionic activator or an ionizing activator or a Lewis base, an alkylaluminum or an alkylaluminoxane (alkylalumoxane). The alkylaluminum may be a trialkylaluminum, alkylaluminum halide or alkylaluminum alkoxide (diethylaluminum ethoxide). Trialkylaluminum can be trimethylaluminum, triethylaluminum (“TEAI”), tripropylaluminum or tris(2-methypropyl)aluminum. The alkylaluminum halide may be diethylaluminum chloride. The alkylaluminum alkoxide may be diethylaluminum ethoxide. The alkylaluminoxane can be a methylaluminoxane (MAO), ethylaluminoxane, 2-methylpropylaluminoxane or a modified methylaluminoxane (MMAO). Each alkyl of alkylaluminoxane or alkylaluminoxane can independently be a (C1-C7) alkyl, alternatively a (C1-C6) alkyl, alternatively a (C1-C4) alkyl. The molar ratio of the metal of the activator (Al) to the metal of a specific catalytic compound (catalytic metal, e.g. Zr) may be 1,000:1 to 0.5:1, alternatively 300:1 to 1:1, alternatively 150 :1 to 1:1. Suitable activators are commercially available.

[0062] Since the first activator is bis(2-(pentamethylphenylamido)ethyl)-amine zirconium dibenzyl and (methylcyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl)zirconium dimethyl bimodal catalyst system come into contact, the catalysts of the bimodal catalyst system are activated and a first species of the activator can be produced in situ. Once the second activator and the balancing catalyst (a dialkyl of (methylcyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl)zirconium) come into contact, the balancing catalyst is activated and a second activator species can be produced in situ. The activator species may have a different structure or composition than the activator from which it is derived and may be a byproduct of catalyst activation or may be a derivative of the byproduct. The corresponding activator species can be a Lewis acid derivative, non-coordinating ionic activator, ionizing activator, Lewis base, alkylaluminum or alkylaluminoxane, respectively. An example of the byproduct derivative is a species of methylaluminoxane that is formed by devolatilization during spray drying of a bimodal catalyst system produced with methylaluminoxane.

[0063] Each contact step between the activator and the catalyst can be carried out independently: (a) in a separate container outside the GPP reactor (e.g. outside the FB-GPP reactor), (b) in a feed to the GPP reactor, and/or (c) inside the GPP reactor (in situ). In option (a), the bimodal catalyst system, once its catalysts are activated, can be fed to the GPP reactor with a dry powder, alternatively with a slurry in a non-polar, aprotic (hydrocarbon) solvent. In option (c), the bimodal catalyst system may be fed to the reactor prior to activation via a first feed line, the first activator may be fed to the reactor via a second feed line, the balancing catalyst may be powered by the reactor via a third supply line and the second activator may be powered by the reactor via a fourth supply line. Any one of the two from the first to the fourth power lines can be the same or different. The activator (or activators) may be fed into the polymerization reactor in “wet mode” and in the form of a solution thereof in an inert liquid, such as mineral oil or toluene, in slurry mode, as a suspension or, in dry mode, as a powder. Each contacting step may be carried out in separate vessels, feed lines or reactors at the same or different times, or in the same vessel, feed line or reactor at different times, to separately provide the bimodal catalyst system and the bimodal catalyst system. balance. Alternatively, the contacting steps can be carried out in the same vessel, feed line or reactor at the same time to provide a mixture of the bimodal catalyst system and the in situ equilibrium catalyst.

Composition of ethylene-co-1-hexene bimodal copolymer

[0064] Ethylene. A monomer with the formula H2C=CH2.

[0065] 1-hexene. A monomer with the formula H2C=C(H)CH2CH2CH2CH3.

[0066] Ethylene-co-1-hexene copolymer or poly(ethylene-co-1-hexene) copolymer is a macromolecule that comprises, alternatively consists essentially of, alternatively consists of, constituent units derived from ethylene monomer and constituent units derived from 1-hexene comonomer. “Consisting essentially of” means that the macromolecule is free of constituent units not derived from ethylene or 1-hexene. “Consisting of” means that the macromolecule is free of constituent units not derived from ethylene or 1-hexene and is composed only of carbon and hydrogen atoms.

[0067] Bimodal ethylene-co-1-hexene copolymer composition. A macromolecule, or collection of macromolecules, composed of repeating units, wherein 50.0 to <100 mol% (mol%), alternatively 70.0 to 99.99 mol%, alternatively 95.0 to 99, 9 mol% of such repeating units are derived from ethylene monomer, and from >0 to 50.0 mol%, alternatively from 0.01 to 30.0 mol%, alternatively 0.1 to 5.0% in moles of the remaining repeating units are comonomer units derived from 1-hexene; or collection of such macromolecules. The collection of macromolecules is characterized by two distinct peaks (not bumps) on a plot of dW/dLog (Mw) on the y-axis versus Log (Mw) on the x-axis to provide a Gel Permeation Chromatography (GPC) chromatograph in that Log (Mw) and dW/dLog (Mw) are as defined below and measured by the Gel Permeation Chromatography (GPC) Test Method described herein.

[0068] The bimodal ethylene-co-1-hexene copolymer composition is a high-density, high-molecular-weight polyethylene (HDPE HMw). The ethylene-co-1-hexene bimodal copolymer composition may further be characterized by any of the following limitations: a weight average molecular weight (Mw) of 200,000.0 to 400,000.0 grams per mole (g/mol) , alternatively from 250,000.0 to 320,000.0 g/mol; a number average molecular weight (Mn) of 6,000.0 to 11,000.0 g/mol, alternatively of 7,000.0 to 9,000.0 g/mol; a z-average molecular weight (Mz) of 1,200,000.0 to 2,500,000.0 g/mol; a combination of any two of the same; and a combination of all three of the same; all measured according to the Gel Permeation Chromatography (GPC) Test Method.

[0069] The bimodal ethylene-co-1-hexene copolymer composition, the tube and the manufacturing methods thereof are free of Ti and Cr metals.

[0070] The polymerization conditions in the method to synthesize are effective to produce the bimodal ethylene-co-1-hexene copolymer composition, characterized by the previously described melt space and, optionally, the properties of the resin and/or properties of the pipe.

Pipe

[0071] The tube. A wall or tube of cylindrical shape with proximal and distal ends (openings) and defining a volumetric space between them and through which a fluid (gas, vapor or liquid) or particulate solid can be transported. The tube wall is defined by a thickness, and the tube size is defined by its outer diameter and length. Resizing the pipe means changing the outside diameter of the pipe. The pipe wall can be any shape, including smooth, rough, circular, ovoid, variable thickness, or constant thickness. The tube can be straight, bent or curved. The volumetric space or capacity of the tube is defined by its internal diameter and length. The tube may be a solid wall tube or a sealed seam wall tube, depending on whether the tube is made by (i) extrusion of a melt through an annular die or (ii) extrusion and spiral winding of the melt around of a mandrel, configured to form an unsealed splice profile and splice seal, respectively. Solid wall pipe can be made in outer diameters from 1.2 to 160 centimeters (cm). Sealed seam wall pipe can have an outer diameter of up to about 3 meters.

[0072] The tube may optionally contain zero, one or more tube additives. The "pipe additive" is a compound or material other than a polyolefin polymer that imparts one or more properties and/or enhances one or more properties of the pipe. Examples of tube additives are antimicrobial agents, antioxidants, catalyst neutralizers (from single-site catalysts), dyes, and light stabilizers. The pipe additive (or additives), when present, may be pre-mixed with the ethylene-co-1-hexene bimodal copolymer composition prior to the melting step in the pipe manufacturing method. Alternatively, the pipe additive (or additives) may be added to the melt of the ethylene-co-1-hexene bimodal copolymer composition during or after the melting step and before the extrusion step in the pipe manufacturing method. When two or more tube additives are used, the one or more tube additives may be premixed with the ethylene-co-1-hexene bimodal copolymer composition prior to the melting step in the method for producing the tube and one or more More pipe additives can be added to the melt of the ethylene-co-1-hexene bimodal copolymer composition during or after the melting step and before the extrusion step in the pipe manufacturing method. In some aspects, the tube consists essentially of the ethylene-co-1-hexene bimodal copolymer composition, at least one antioxidant, and at least one catalyst neutralizer.

[0073] The tube is useful for transporting fluids. Examples of such fluids are natural gas, crude oil, refined petroleum products, ethylene, alpha-olefins, water (cold or hot), aqueous mixtures of solutes. The tube can be used in housing, infrastructure, construction, factory buildings and hydrocarbon transport pipelines.

[0074] The tube can be characterized as having the necessary properties to meet ISO requirements for PE100 and/or PE100 RC tube applications. The “RC” in PE100 RC means crack resistant. ISO requirements for PE100 pipe applications are specified in ISO 4427 for water pipe applications and ISO 4437 for gas pipes. Requirements for PE100 RC pipe applications are specified in PAS1075.

[0075] Alternatively, a different modality is preceded. ASTM means ASTM International Standards Organization, West Conshohocken, Pennsylvania, USA. Any comparative example is used for illustration purposes only and need not relate to the prior art. Free from or lacking means a complete absence of; alternatively, not detectable. ISO is the International Organization for Standardization, Chemin de Blandonnet 8, CP 401 - 1214 Vernier, Geneva, Switzerland. IUPAC is the International Union of Pure and Applied Chemistry (IUPAC Secretariat, Research Triangle Park, North Carolina, USA). "May" confers a permissible choice, not an imperative choice. Operative means functionally capable or effective. Optional(mind) means to be absent (or excluded), alternatively, to be present (or included). PAS is Publicly Available Specification, Deutsches Institut für Normunng e.V. (DIN, German Institute for Standardization) Properties can be measured using standard test methods and conditions. Ranges include endpoints, subranges, and integer and/or fractional values included therein, except that an integer range does not include fractional values. Ambient temperature: 23 °C. ± 1°C.

Examples

[0076] Accelerated full notch creep test (FNCT) method: measured in accordance with ISO 16770: 2004 at 90 °C, determined at a true stress of 5.0 MPa in 2 wt% lauramine oxide in water. ISO 16770:2004 (last revised and confirmed in 2014), Plastics - Determination of environmental stress cracking (ESC) of polyethylene - Full notch creep test (FNCT - Plastics - Determination of environmental stress cracking (ESC) of polyethylene - Full -notch creep test). 2% by weight lauramine oxide in water can be made by diluting with Dehyton PL water, which is an aqueous solution of 25.0 to 50.0% by weight of lauramine oxide and is sold by BASF.

[0077] Bimodality Test Method: determines the presence or absence of resolved bimodality by plotting dWf/dLogM (mass detector response) on the y-axis versus LogM on the x-axis to obtain a GPC chromatogram curve that contains maximum values log(Mw) locations for LMw and HMw polyethylene component peaks, and observe the presence or absence of a local minimum between the LMw and HMw polyethylene component peaks. The dWf is the change in weight fraction, dLogM is also referred to as dLog(Mw) and is the change in the logarithm of the molecular weight, and LogM is also referred to as Log(Mw) and is the logarithm of the molecular weight.

[0078] Butyl Branch Frequency (BBF) Test Method: The comonomer content is determined using 13C NMR analysis in accordance with the techniques described, for example, in Patent No. US 5,292,845 (Kawasaki et al.) and by JC Randall in Rev. Macromol. Chem. Phys., C29, 201 to 317, ranging from zero homopolymer short-chain branches per 1,000 total carbon atoms (0 SCB/1,000 total C) to 50 SCB/1,000 total C, where total C is the sum of carbons in the backbone of the polymer plus the carbons in all branches of the polymer. In the poly(ethylene-co-1-hexene) copolymer, most or all of the branches are butyl groups (e.g., -(CH2)3CH3) and the butyl branching frequency (BBF) is equal to the number of branches of butyl per 1,000 C.

[0079] Deconvolution Test Method: segments the chromatogram obtained using the Bimodality Test Method into nine (9) Schulz-Flory molecular weight distributions. Such a deconvolution method is described in US document No. 6,534,604. Assign the four lowest Mw distributions to the LMw polyethylene component and the five highest Mw distributions to the HMw polyethylene component. Determine the respective weight percentages (wt%) for each of the LMw and HMw polyethylene components in the ethylene-co-1-hexene bimodal copolymer composition using summed values of the weight fractions (Wf) of the ethylene-co-1-hexene components. polyethylene LMw and HMw and the respective number-average molecular weights (Mn) and weight-average molecular weights (Mw) by the known mathematical treatment of the Schulz-Flory aggregate Mw distributions.

[0080] Density is measured in accordance with ASTM D792-13, Standard Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement, Method B (for testing solid plastics in liquids other than water, e.g. in liquid 2-propanol). Report results in units of grams per cubic centimeter (g/cm3).

[0081] Gel Permeation Chromatography (GPC) Method: Weight Average Molecular Weight Test Method: determine Mw, average numerical molecular weight (Mn) and Mw/Mn using chromatograms obtained on a Permeation Chromatography instrument in High Temperature Gel (HTGPC, Polymer Laboratories). The HTGPC is equipped with transfer lines, a differential refractive index (DRI) detector, and three 10 μm Polymer Laboratories PLgel Mixed-B columns, all contained in an oven maintained at 160 °C. The method uses a solvent composed of TCB treated with BHT at a nominal flow rate of 1.0 milliliter per minute (ml/min) and a nominal injection volume of 300 microliters (μ l). Prepare the solvent by dissolving 6 grams of butylated hydroxytoluene (BHT, antioxidant) in 4 liters (l) of 1,2,4-trichlorobenzene (TCB) reagent grade and filtering the resulting solution through a Teflon filter of 0.1 micrometer (μ m) to supply the solvent. Degas the solvent with an in-line degasser before entering the HTGPC instrument. Calibrate the columns with a series of monodisperse polystyrene (PS) standards. Separately, prepare known concentrations of test polymer dissolved in solvent by heating known amounts thereof in known volumes of solvent to 160°C with continuous stirring for 2 hours to provide the solutions. (Measure all quantities gravimetrically). Target solution concentrations, c, of test polymer of 0.5 to 2.0 milligrams of polymer per milliliter of solution (mg/ml), where lower concentrations, c, are used for higher molecular weight polymers. Before passing each sample, purge the DRI detector. Then increase the flow rate in the device to 1.0 ml/minute and let the DRI detector stabilize for 8 hours before injecting the first sample. Calculate Mw and Mn using universal calibration relationships with column calibrations. Calculate the Mw in each elution volume with the following equation: where the subscript "X" represents the test sample, the subscript "PS" represents PS standards, APS =0.67, KPS = 0.000175, and KX and AX are obtained from published literature. For polyethylenes, ax/Kx = 0.695/0.000579. For polypropylenes, ax/Kx = 0.705/0.0002288. At each point in the resulting chromatogram, calculate the concentration, c, from a DRI signal subtracted from the reference base, IDRI, using the following equation: c = KDRIIDRI/(dn/dc), where KDRI is a constant determined by calibrating the DRI, / indicates division and dn/dc is the refractive index increment for the polymer. For polyethylene, dn/dc = 0.109. Calculate the mass recovery from the ratio of the integrated area of the concentration chromatography chromatogram over the elution volume and the injection mass that is equal to the predetermined concentration multiplied by the injection closed circuit volume. Report all molecular weights in grams per mole (g/mol) unless otherwise noted. Additional details regarding the methods for determining Mw, Mn, MwD are described in document No. US 2006/0173123, pages 24 to 25, paragraphs [0334] to [0341]. Plot dW/dLog (Mw) on the y axis versus Log(Mw) on the x axis to provide a GPC chromatogram, where Log(Mw) and dW/dLog (Mw) are as defined above.

[0082] Load Melt Index (HLMI) Test Method I21: use ASTM D1238-13, Standard Test Method for Melt Flow Rates of Thermoplastics by Extrusion Platomer, using conditions of 190 ° C/ 21.6 kilograms (kg). Report results in units of grams eluted for 10 minutes (g/10 min).

[0083] Melt Index Test Method (“I2”): for ethylene-based (co)polymer is measured in accordance with ASTM D1238-13, using conditions of 190 °C/2.16 kg , previously known as “Condition E”.

[0084] Melt Indicator Test Method (“I5”): use ASTM D1238-13, using conditions of 190 °C/5.0 kg. Report results in units of grams eluted for 10 minutes (g/10 min).

[0085] Melt Flow Ratio Test Method MFR5 (“I21/I5”): calculated by dividing the value of the HLMI Test Method I21 by the value of the Melt Ratio Test Method I5.

[0086] Melt resistance test method: using a Gottfert Rheotens tester, at a test temperature of 190 °C. The test uses a die with a length of 30 mm and an inner diameter of 2 mm. The acceleration is 2.4 millimeters per second per second (mm/s2). The peak melt strength value is the highest value observed over a speed range of 10 to 50 mm/s). Average melt strength is an average of melt strength values measured over a speed range of 35 to 50 mm/s. Strain hardening modulus is measured in accordance with ISO 18488:2015, Polyethylene (PE) materials for piping systems - Determination of strain hardening modulus in relation to slow crack growth - Test method (olyethylene (PE) ) materials for piping systems - Determination of Strain Hardening Modulus in relation to slow crack growth - Test Method).

[0087] Shear thinning index (SHI) test method: Use dynamic mechanical spectroscopy (DMS). Compression mold a test sample with a Carver press onto a 25 x 3 mm circular plate at 190 °C for 6.5 minutes under 9070 kg in air. Remove the plate from the press and place it on a bench to cool. Using the plate, perform a constant temperature frequency sweep using the ARES Classic or ARES-G2 strain-controlled rheometer equipped with 25 mm (diameter) parallel plates under a nitrogen purge. Place the plate on the board and let it melt for 5 minutes at 190°C. Close the boards to a 2 mm gap, trim the portion of the board that extends beyond the circumference of the boards, and begin the constant temperature frequency sweep with a 5 minute delay to allow temperature equilibration. Perform operations at 190 °C over a frequency range of 0.01 radians per second (rad/s) to 100 rad/s at 5 points per decade range. Keep the deformation amplitude constant at 10%. The rheometer applies a shear deformation in the form of stress to the plate and measures the response torque. Report the results as complex viscosity n*, tan (δ) or tan delta, viscosity, G', G" and G*. Calculate the shear thinning index (abbreviated "SHI (0.01/100)" or "00 .01/100" or "πo,oi/nioo") equals the complex viscosity at 0.01 rad/s divided by the complex viscosity at 100 rad/s.

[0088] Antioxidant: 1. Pentaerythritol tetracis (3-(3,5-di(1',1'-dimethylethyl)-4-hydroxyphenyl)propionate); obtained as IRGANOX 1010 from BASF.

[0089] Antioxidant 2. Tris(2,4-di(1‘,1‘-dimethylethyl)-phenyl)phosphite. Obtained as IRGAFOS 168 from BASF.

[0090] Carbon black masterbatch 1: 40% by weight of P-type carbon black, with a particle size of less than 10 nm, in a linear low-density polyethylene carrier resin. Obtained as LL2590 from Cabot Corporation.

[0091] Catalyst neutralizer: 1. Calcium Stearate.

[0092] Bimodal Catalyst System 1 (BMC1): a spray-dried catalyst formulation prepared from Cabosil™ TS-610, methylalumoxane, bis(2-(pentamethylphenylamido)ethyl)-zirconium amine and cyclopentadienyl dimethyl) (1,3-dimethyl-4,5,6,7-tetrahydroindenyl)zirconium.

[0093] Bimodal Catalyst System 2 (BMC2): a spray-dried catalyst formulation prepared from Cabosil™ TS-610, methylalumoxane and zirconium bis(2-(pentamethylphenylamido)ethyl)-amine dibenzyl.

[0094] Bimodal Catalyst System 3 (BMC3): PRODIGY™ BMC-200 from Univation Technologies, LLC, Houston, Texas, USA, defined by bis(2-pentamethylphenylamido)ethyl)amine zirconium dibenzyl and (tetramethylcyclopentadienyl)(n-propylcyclopentadienyl )spray-dried zirconium dichloride at a 3:1 molar ratio in CAB-O-SIL TS610, a hydrophobic fumed silica made by surface treating hydrophilic (untreated) fumed silica supported by dimethyldichlorosilane and methylaluminoxane (MAO).

[0095] Equilibrium catalyst 1 (TC1): a 0.04% by weight solution of (methylcyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl)zirconium dimethyl in isopentane.

[0096] Equilibrium Catalyst 2 (TC2): PRODIGY™ UT-TR-200 from Univation Technologies, LLC, defined by (tetramethylcyclopentadienyl) (n-propylcyclopentadienyl)dimethyl zirconium (procatalyst) dissolved in heptane to give a solution with a concentration of 0.7 grams of procatalyst per milliliter of solution (g/mL).

[0097] Comonomer: 1-hexene or H2C=C(H)(CH2)3CH3.

[0098] Ethylene (“C2”): CH2=CH2.

[0099] Molecular hydrogen gas: H2.

[0100] Inventive Example 1 (IE1): polymerization procedure. It is carried out in a semi-commercial scale reactor with the Bimodal Catalyst System 1 (BMC1), Equilibrium Catalyst 1 (TC1) and 1-hexene comonomer according to the method described previously, adjusting the polymerization conditions that include temperature of the reactor bed, H2/C2 molar ratio, C6/C2 molar ratio and TC1 feed rate to provide an embodiment of the ethylene-co-1-hexene bimodal copolymer composition as granular resins. Polymerization operating conditions are reported in Table 1.

[0101] Inventive Example 2 (IE2): polymerization procedure. It is performed in a pilot plant reactor Bimodal Catalyst System 2 (BMC2) used, Equilibrium Catalyst 1 (TC1) and 1-hexene comonomer according to the method described previously, adjusting the polymerization conditions comprising bed temperature of the reactor, H2/C2 molar ratio, C6/C2 molar ratio and TC1 feed rate to provide embodiments of the ethylene-co-1-hexene bimodal copolymer composition as granular resins. Polymerization operating conditions are reported in Table 1. IE2 is excluded as an inventive example in embodiments that include the melting property (c) shear dilution index of 96 to 125.

[0102] Control Example 1 (CE1): polymerization procedure for CE1: It is performed in a semi-commercial scale reactor with the Bimodal Catalyst System 3 (BMC3), Equilibrium Catalyst 2 (TC2) and 1-hexene comonomer of according to the method described previously, adjusting polymerization conditions comprising reactor bed temperature, H2/C2 molar ratio, C6/C2 molar ratio and TC2 feed rate to provide a bimodal ethylene-co-1 copolymer composition -hexene as granular resins. Table 1 reports the polymerization operating conditions. Table 1: Operating conditions from IE1 to IE2 to CE1 *S,CM, FB, GPP: gas phase polymerization in simple fluidized bed, continuous mode.** pilot plant reactor did not operate in condensation mode. ARx pressure (kPa): total reactor pressure in kilopascals.

[0103] As shown in Table 1, the operating conditions used to produce the bimodal ethylene-co-1-hexene copolymers of IE1 to IE2 comprise the bimodal catalyst system, equilibrium catalyst, a bed temperature of 99.9 °C to 105.0 °C; an ethylene partial pressure (C2) of 1,516 to 1,517 kpa; an H2/C2 molar ratio of 0.00229 to 0.00280; a C6/C2 molar ratio of 0.00560 to 0.00703; a superficial gas velocity of 0.555 to 0.643 m/s (meter per second). In certain embodiments, the method for synthesizing the bimodal ethylene-co-1-hexene copolymer composition employs the aforementioned operating conditions.

[0104] Formulation and pelletizing procedure: Each of the different granular resins from IE1 to IE2 and CE1 were mixed separately with 1,500 parts per million weight/weight (ppm) of antioxidant 1, 500 ppm of antioxidant 2 and 1,000 ppm of neutralizer. catalyst 1 and 5.6 wt% carbon black masterbatch 1 (to provide a final formulation with 2.25 wt% carbon black) in a ribbon mixer and then compounded into cut pellets of wire using a Coperion ZSK-40 twin screw extruder. The resulting pellets of each resin were tested for melt properties of HLMI (I21), MFI (5 kg), MFR5 (I21/I5) and melt strength according to their respective test methods mentioned above. The results are reported below in Table 2. In certain embodiments, the ethylene-co-1-hexene bimodal copolymer composition further comprises at least one antioxidant selected from Antioxidants 1 and 2; at least one catalyst neutralizer selected from Catalyst Neutralizers 1 and 2; or a combination thereof.Table 2: Fusion properties of IE1 to IE2 and CE1

[0105] As shown in Table 2, the melting properties of the bimodal ethylene-co-1-hexene copolymer compositions of IE1 to IE2 comprise a high load melt index I21 (190 °C, 21.6 kg) of 5.41 to 5.72 g/10 min; a melt flow index I5 (190° C., 5.0 kg) of 0.183 to 0.21 g/10min; an MFR5 melt flow ratio (I21/I5) of 27.0 to 29.5; and a melt strength of 19 to 21 cN (19.6 to 20.0 cN). In certain embodiments, the ethylene-co-1-hexene bimodal copolymer composition is characterized by any one, alternatively all but one, alternatively each of the melting properties.

[0106] Granular resins from IE1 to IE2 and CE2 were characterized by density; butyl branching frequency per 1,000 carbon atoms (bbf/1000C); molecular mass dispersion (Mw/Mn), DM and weight average molecular weight, numerical and z according to their respective test methods mentioned above. The results are reported below in Table 3.Table 3: Resin properties from IE1 to IE2 and CE1

[0107] As shown in Table 3, the resin properties of the ethylene-co-1-hexene bimodal copolymer compositions of IE1 to IE2 comprise a density of 0.9486 to 0.9584 g/cm3; a division of the highest molecular weight component (HMw) from 36.9 to 49.1% by weight; a division of the lowest molecular weight (LMw) component from 63.1 to 50.9% by weight, respectively; a number average molecular weight of 14,900 to 23,100 g/mol; a weight average molecular weight of 333,300 to 354,100 g/mol; a molecular mass dispersion Mw/Mn (MD) of 15.3 to 22.4; a z-average molecular weight of 2,462,000 to 3,086,000 g/mol; and a butyl branch frequency of 1.4 to 1.43 per 1,000 carbon atoms. In certain embodiments, the ethylene-co-1-hexene bimodal copolymer composition is characterized by any one, alternatively all but one, alternatively each of the properties of the resin.

[0108] Tube forming procedure: Granular resin pellets of the bimodal ethylene-co-1-hexene copolymer composition of IE1 to IE2 and CE1 are melted separately at the melting temperature described herein and separately and extruded into SDR11 tubes of 25 .4 centimeters (cm, 10 inches) using a standard Davis 130 mm grooved tube extrusion machine. SDR11 tubes were evaluated for resistance to critical pressure for rapid crack propagation (ISO 13477). Resistance to slow crack growth measured by strain hardening modulus and accelerated FNCT. See Table 4.Table 4: Tube properties from IE1 to IE2 and CE1

[0109] As shown in Table 4, the tube properties of the bimodal ethylene-co-1-hexene copolymer compositions of IE1 to IE2 comprise a strain hardening modulus and an accelerated creep test performance of 473 to 531 hours . In certain embodiments, the ethylene-co-1-hexene bimodal copolymer composition and tubes thereof are independently characterized by any, alternatively all but one, alternatively each of the aforementioned tube properties. Without wishing to be limited by theory, it is believed that the bimodal ethylene-co-1-hexene copolymer composition at a given density has improved performance in accelerated FNCT due to its combination of Mw/Mn and comonomer distribution properties. For example, the ethylene-co-1-hexene bimodal copolymer composition has a greater amount of comonomer unit content in the HMw component at a given composition density than the comparative ethylene/1-hexene bimodal copolymers. This enhancement means that the composition of the bimodal ethylene-co-1-hexene copolymer is improved for use as a resin to produce PE100 and PE100 RC pipes.

Claims (8)

1. Bimodal ethylene-CO-1-hexene copolymer composition, characterized by having a density of 0.945 to 0.960 grams per cubic centimeter (g/cm3), measured in accordance with ASTM D792-13, Method B; a molecular mass dispersion (Mw/Mn), MD, of 11.0 to 25.0, where Mw and Mn are measured according to the Gel Permeation Chromatography (GPC) Test Method; and consisting of a higher molecular weight ethylene-CO-1-hexene copolymer component (HMW component) having a molecular weight distribution (Mw/Mn) greater than 3.75 (>3.75) and a homopolymer of lower molecular weight polyethylene or a lower molecular weight ethylene-CO-1-hexene copolymer component (LMW component), with the LMW component having a molecular weight distribution (Mw/Mn) of 2.75 to 3 .35; and having a component fraction division defined by a weight fraction of the HMW component of 35.0 to 65.0% by weight and a weight fraction of the LMW component fraction of 65.0 to 35.0% by weight, respectively, from the combined weight of the HMW and LMW components, measured according to the GPC test method; and wherein, when in molten form at 190°C, the ethylene-CO-1-hexene bimodal copolymer composition is defined by the properties (a), (b) and optionally (c): (a) a flow index melt strength (5 kg) (I5 or MFI5) of 0.15 to 0.30 grams per 10 minutes (g/10 min), (b) peak melt strength of 18 to 29 centiNewtons (cN), and optionally (c) shear thinning index, 00.01/0100, from 96 to 125; and, when in solid form, the bimodal ethylene-CO-1-hexene copolymer composition is defined by properties (d) and (e): (d) strain hardening modulus of 50.0 to 75 megapascals (MPa) and (e) accelerated full notch creep test (FNCT) performance of 401 to 700.0 hours; where the melt flow index (5 kg) is measured in accordance with ASTM D1238-13 (190 °C, 5.0 kg), the shear thinning index is measured in accordance with the Index Test Method shear thinning (190 °C), the peak melt strength is measured at the highest peak on a VERSUS melt strength graph over a speed range of 10 to 50 millimeters per second (mm/s) according to the Melt Strength Test Method, strain hardening modulus is measured in accordance with ISO 18488:2015, and accelerated FNCT performance is measured in accordance with ISO 16770:2004 at 90 °C and under a true stress of 5.0 MPa in 2 weight percent (wt%) lauramine oxide in water. 2. Bimodal ethylene-CO-1-hexene copolymer composition according to claim 1, characterized by the fact that it is in accordance with any of the property limitations (i) to (viii): (i) the density is from 0.9450 to 0.9590 g/cm3; (ii) the component fraction division is defined by a weight fraction of the HMW component of 44.0 to 52.0% by weight; and a weight fraction of the LMW component fraction of 56.0 to 48.0 wt%, respectively, of the combined weight of the HMW and LMW components; (iii) the molecular mass dispersion (Mw/Mn), DM, is 11.0 to 23.0; (iv) (a) MFI5 is 0.15 to 0.24 g/10 min; (v) (c) shear dilution index, r|0.01 /q 100, is 99 to 115; (vi) (b) peak melting strength is 20.0 to 28 cN; (vii) (d) strain hardening modulus is 55 to 70.0 MPa; and (viii) (e) performance of the accelerated FNCT is 401 to 600.0 hours. 3. Bimodal ethylene-CO-1-hexene copolymer composition according to any one of claims 1 or 2, further characterized by the fact that it is in accordance with any of the melting property limitations (i) to (iii) : (i) a high load melt index of 1 to 10 g/10 min, measured in accordance with ASTM D1238-13 (190 °C, 21.6 kg, HLMI or I21); (ii) a melt flow ratio I21/I5 ("MFR5") of 20 to 40, the I21 and I5 values used to calculate the MFR5 are each in g/10 min and are measured accordingly with ASTM D1238-13 (190 °C, 21.6 kg, "I21"; and 190 °C, 5.0 kg, "I5", respectively); (iii) both (i) and (ii). 4. Bimodal ethylene-CO-1-hexene copolymer composition according to any one of claims 1 to 3, further characterized by the fact that it is in accordance with any of the resin property limitations (i) to (iv) : (i) a weight average molecular weight (Mw) of 300,000 to 400,000 grams per mole (g/mol); (ii) a number average molecular weight (Mn) of 10,000 to 30,000 grams g/mol; (iii) a z-average molecular weight (Mz) of 2,000,000 to 3,400,000 g/mol; (iv) a butyl branch frequency per 1,000 carbon atoms (bbf/1,000C) of 1.2 to 1.5, as measured in accordance with the Butyl Branch Frequency Test Method; and where Mw, Mn and Mz are measured according to the GPC test method. 5. Method for synthesizing the bimodal ethylene-CO-1-hexene copolymer composition as defined in any one of claims 1 to 4, the method being characterized by the fact that it consists of copolymerizing ethylene and 1-hexene and copolymerizing ethylene fresh and optionally fresh 1-hexene, with a combination of a bimodal catalyst system and an equilibrium catalyst in the presence of molecular hydrogen gas and optionally an induced condensation agent in a polymerization reactor under effective polymerization conditions to provide a starting ethylene-CO-1-hexene bimodal copolymer composition; wherein the bimodal catalyst system is made by placing a first activator in contact with bis(2-(pentamethylphenylamido)ethyl)-amine zirconium dibenzyl and dimethyl (methylcyclopentadienyl)(1,3-dimethyl-4,5,6 ,7-tetrahydroindenyl)zirconium; wherein the equilibrium catalyst is made by placing a second activator in contact with (methylcyclopentadienyl)(1,3-dimethyl-4,5,6,7-tetrahydroindenyl)zirconium dimethyl; the first and second activators being the same or different; and wherein effective polymerization conditions comprise a reactor bed temperature of 90 degrees (°) to 110° Celsius (C); a molar ratio of molecular hydrogen gas to ethylene of 0.001 to 0.0050; and a molar ratio of 1-hexene to ethylene of 0.00450 to 0.01000. 6. Tube, characterized by the fact that it consists of the bimodal ethylene-CO-1-hexene copolymer composition, as defined in any one of claims 1 to 4. 7. Method for producing a tube, the method for producing a tube being characterized by the fact that it comprises steps (A), (B1) or (B2), optionally (C) and (D): (A) melting the ethylene-CO-1-hexene bimodal copolymer composition as defined in any one of claims 1 to 4 to provide a melt thereof; (81) extruding the melt through an annular die configured to form a cylinder to make an initial solid-wall cylinder of the bimodal ethylene-CO-1-hexene copolymer composition or (82) extruding and rolling the melt spirally around a mandrel configured to form an unsealed splice profile wall, so as to make an unsealed splice profile wall, and heat fuse the unsealed splice to the unsealed splice profile wall to make an initial sealed seam wall cylinder; (C) optionally resizing the initial solid wall cylinder or the initial sealed seam wall cylinder to make a resized wall cylinder with a different diameter; and (D) cooling the initial solid wall cylinder, the initial seam wall cylinder, or the resized wall cylinder, thereby forming a solid wall tube or a sealed seam wall tube, respectively. 8. Manufactured article, characterized by the fact that it comprises the composition of bimodal ethylene-CO-1-hexene copolymer, as defined in any one of claims 1 to 4, wherein the manufactured article is different from a tube.